The ASU Center for Meteorite Studies is pleased to announce that Emily Worsham, a graduate student at the University of Maryland, is the recipient of the 2016 Nininger Meteorite Award.

Emily's paper “Siderophile element systematics of IAB complex iron meteorites: New insights into the formation of an enigmatic group” (coauthored by Katherine Bermingham, and Richard Walker) addresses the disputed origins of IAB iron meteorites. The IAB complex is a large group of chemically and texturally similar meteorites containing a main group and several chemical subgroups. The complex likely represent metals with a thermal history unlike most other iron meteorite groups, which sample the fractionally-crystallized cores of differentiated planetesimals. Opposing models for the formation of the IAB complex invoke either an internal (decay of 26Al) or external (impact-generated) heat source. This paper details a comprehensive study of highly siderophile element (HSE) characteristics and Re-Os isotope systematics, along with trace element modeling within the subgroups, to elucidate the crystallization mechanisms of IAB melts and the degree of differentiation of the IAB parent body(ies).

The absolute and relative HSE abundances indicate that the IAB subgroups formed from a minimum of five separate parental melts. Most subgroups crystallized by complex crystal-liquid fractionation and mixing processes, indicating that the initial melts may have been impact-generated. The characteristics which distinguish some IAB complex irons from fractionally-crystallized iron meteorite groups likely originated because of their formation on undifferentiated parent bodies where impacting and mixing processes were important. Thus, many IAB irons appear to sample a type of parent body intermediate between primitive and fully differentiated parent bodies; a finding which has implications for why and how some asteroids differentiated into a core, mantle, and crust, and why some did not.

Note that the application period for the 2016 Nininger Meteorite Award has closed.

History of the Award

In 1965, Dr. H.H. Nininger and Mrs. Addie D. Nininger endowed the Nininger Science of Meteoritics Fund to the Center for Meteorite Studies at Arizona State University in order to promote interest in meteorite-related topics among young scientists. The Fund supports the Nininger Meteorite Award, which recognizes outstanding student achievement in the “Science of Meteoritics” as embodied by an original research paper. Past recipients include Harry Y. McSween (University of Tennessee), Edward Stolper (California Institute of Technology) and the recipients of the 2010 Barringer Award (William K. Hartmann, Planetary Science Institute), 2002 Nier Prize (Dante Lauretta, University of Arizona), and 2005 Leonard Medal (Joseph Goldstein, University of Massachusetts, Amherst).

The original text of the Nininger endowment states that the "Science of Meteoritics embraces all aspects of the study of inert natural matter existing in space, passing through the atmosphere, or having come to Earth from space, together with any or all of the phenomena occasioned by its fall and its effect upon the Earth or upon any other member of the Solar System. Such science shall also be considered to include theoretical consideration as to the origin of such matter and special relationships". Research topics covered under this description include, but are not limited to, physical and chemical properties of meteorites, origin of meteoritic material and cratering. Observational, experimental, statistical or theoretical investigations are allowed.

Eligibility Requirements

Applicant must be an undergraduate or graduate student enrolled at a United States college or university.

The student must be first author of the paper, but does not have to be the sole author.

Paper must cover original research conducted by the student, and have been written, submitted or published between January 1, 2016 and December 31, 2016.

Application

As a part of your application, we require a letter of support from your advisor. Please have your advisor email the letter to nininger [at] asu.edu. When both your application and letter of support are on file, we will inform you that your application is complete.